The subject matter herein relates generally to electronic devices, such as transformers, inductors, baluns, couplers, or filters.
Some known electronic devices include planar bodies, such as circuit boards, that include one or more magnetic components built into the planar bodies. The magnetic component can include a ferrite core with conductive winding extending around the ferrite core. Some of these magnetic components include two conductive windings that are not conductively coupled with each other. For example, the conductive windings may not be physically or mechanically coupled such that electric current cannot flow through one conductive winding directly to the other conductive winding. The current flowing through one winding generates a magnetic field in the core and in the other winding. The magnetic field in the other winding generates an electric current. The electrical performance of the device is determined by a variety of parameters, such as the ratio of the number of turns in the first winding to the number of turns in the second winding, the shape of the first and/or second windings, the impedance of the first and second windings, and the like.
The manufacturing process of some known planar electronic devices includes drilling or routing a planar board substrate. More specifically, the planar board substrate may include a plurality of substrate layers (e.g., FR-4 and other PCB-type materials). Portions of the substrate layers may be removed through controlled depth routing. In controlled depth routing, a drill bit is moved along a predetermined path to remove substrate material and provide a recess or cavity within the planar board substrate. The recess does not extend entirely through the planar board substrate. After forming the recess, a magnetic core (e.g., ferrite core) may be loaded into the recess. Although controlled depth routing is capable of providing sufficient recesses during the manufacture of planar electronic devices, in some cases the controlled depth routing can add significant costs to the planar electronic devices.
Accordingly, there is a need for a less expensive method of manufacturing a planar board substrate.